Various types of heat exchange towers are in wide use in industry. Such towers include cooling towers which are utilized to cool a fluid by contact with ambient air, as well as heating towers which are used to heat a fluid by contact with ambient air. In the case of such towers, a fan typically blows air through the tower, with air pulled into an inlet at the bottom or sides of the tower. Inside the tower, the air typically passes through a fill media which may, for example, include splash bars or a pack of corrugated sheets. In some towers, fluid to be heated or cooled may be sprayed from above the fill so that it falls through the fill, so that the interaction of the air and the fill will impart heating or cooling to the fluid as it falls. The fluid is then typically collected in a basin at the bottom of the tower.
One application for heating towers is in the field of liquid natural gas (LNG) vaporization. One example of an LNG tower would be to take cold fluid from an LNG condenser and heat it using the ambient air before returning the fluid to the condenser.
Various types of tower arrangements are known, including, for example, a counterflow tower in which the air enters and leaves from opposed sides of the tower, or a counterflow tower where air typically enters via one or more inlets at the lower side of the tower below the fill and is exhausted by a fan outlet either upwardly out of the top of the tower, or sideways out of an outlet in a top side of a tower above the fill.
In such arrangements, it is generally desirable to reduce the energy load that must be imparted by the fan in order to draw the desired airflow through the system. This reduces the total energy use of the tower and therefore makes it more economically and environmentally efficient. Also, it is generally desirable to achieve a relatively even distribution of airflow velocity, across all regions of the fill material. Many tower designs are known which have desirable characteristics; however, there is always a need in the art for improved airflow management.